A quarterdeck is the part of a ship intended for use by the commanding officer during ceremonies and official functions. When the ship is in port, it is considered the most important part of the entire vessel, as it serves as the central location from which commands are issued. The captain commands from the head of the quarterdeck, and the navigator uses it when fixing the ship's position on the open waters. Under normal circumstances, the quarterdecks of seafaring vessels are specifically labeled through knotted ropes, lines drawn on the deck, or other types of markings indicating its position and relative importance compared to the rest of the open deck on the ship.
In addition being used for commanding and navigational purposes, the quarterdeck serves as the most formal location on the ship. Individuals manning the quarterdeck must always remain dressed in the uniform of the day, which is the specific military uniform designed for soldiers on that specific day. Others who are not correctly attired will go out of their way to avoid setting foot in this area, as doing so while ill-attired is considered a serious breach of seagoing etiquette. The one exception to this is when crossing the deck is unavoidable during the course of a regular job assignment.
Although cleanliness is generally the norm for most of the ship, as a ceremonial and important location, special attention is paid to the quarterdeck to keep it in the best possible appearance at all times. The crew generally works to keep the quarterdeck free from debris of all kinds, scrubbing and cleaning it as necessary to maintain a pristine appearance. A quarterdeck which is not clean or well cared for may reflect poorly on both the discipline of the crew and the skill of the officers manning the ship.
In addition to protocols regarding who may be on the quarterdeck, there are also specific protocols for boarding the deck. Officers of the ship, along with their visitors, typically use the starboard gangway. All other individuals mount the deck via the port gangway. The one exception to this is during times of foul weather; under these circumstances, all individuals, including officers, will use the lee gangway, which is the one that is downwind.